using UnityEngine;

/// <summary>
/// 主角自动巡逻移动：不再支持点击地面移动（避免与拖动屏幕、建筑放置的输入冲突）。
/// 没有敌人时在己方主建筑周围小范围来回走动，所有移动被限制在基地附近（栓绳范围）。
/// 战斗组件发现敌人后调用 SetPatrolEnabled(false) 停止巡逻进行攻击。
/// </summary>
public class MainCharacterDebugMovement : MonoBehaviour
{
    [Header("巡逻移动")]
    [Min(0f)]
    public float moveSpeed = 4f;

    [Min(0f)]
    public float patrolStopDistance = 0.15f;

    [Min(0f)]
    public float patrolPause = 1.5f;

    [Header("巡逻区域（以主建筑为锚点）")]
    [Min(0f)]
    public float patrolRadius = 5f;

    [Min(0f)]
    public float leashRadius = 8f;

    public string friendlyBuildingTag = "Friend";

    private Animator animator;
    private Transform baseAnchor;
    private Vector3 fallbackAnchor;
    private Vector3 patrolTarget;
    private Vector3 chaseTarget;
    private bool hasPatrolTarget;
    private bool hasChaseTarget;
    private float pauseTimer;
    private bool patrolEnabled = true;

    public bool IsMoving { get; private set; }

    private Vector3 AnchorPosition
    {
        get
        {
            Vector3 position = baseAnchor != null ? baseAnchor.position : fallbackAnchor;
            position.y = transform.position.y;
            return position;
        }
    }

    private void Start()
    {
        animator = GetComponent<Animator>();
        fallbackAnchor = transform.position;
        baseAnchor = FindMainBase();
        SetWalking(false);
    }

    private void Update()
    {
        if (!patrolEnabled)
        {
            UpdateChase();
            return;
        }

        if (pauseTimer > 0f)
        {
            pauseTimer -= Time.deltaTime;
            IsMoving = false;
            SetWalking(false);
            return;
        }

        if (!hasPatrolTarget)
        {
            patrolTarget = GetNextPatrolPoint();
            hasPatrolTarget = true;
        }

        Vector3 toTarget = patrolTarget - transform.position;
        toTarget.y = 0f;

        if (toTarget.magnitude <= patrolStopDistance)
        {
            hasPatrolTarget = false;
            pauseTimer = patrolPause;
            IsMoving = false;
            SetWalking(false);
            return;
        }

        Move(toTarget.normalized);
    }

    private void UpdateChase()
    {
        if (!hasChaseTarget)
        {
            IsMoving = false;
            SetWalking(false);
            return;
        }

        Vector3 toTarget = chaseTarget - transform.position;
        toTarget.y = 0f;

        if (toTarget.magnitude <= patrolStopDistance)
        {
            IsMoving = false;
            SetWalking(false);
            return;
        }

        // 追击同样受栓绳限制，不会完全离开基地
        Move(toTarget.normalized);
    }

    private Transform FindMainBase()
    {
        Transform firstBuilding = null;
        foreach (GameObject candidate in GameObject.FindGameObjectsWithTag(friendlyBuildingTag))
        {
            if (candidate == null || candidate.transform.root == transform.root)
            {
                continue;
            }

            // 主建筑按名称优先匹配；找不到时退回第一个己方建筑
            if (candidate.name.Contains("主要") || candidate.name.Contains("基地"))
            {
                return candidate.transform;
            }

            if (firstBuilding == null)
            {
                firstBuilding = candidate.transform;
            }
        }

        return firstBuilding;
    }

    private Vector3 GetNextPatrolPoint()
    {
        Vector2 offset = Random.insideUnitCircle * patrolRadius;
        return ClampToLeash(AnchorPosition + new Vector3(offset.x, 0f, offset.y));
    }

    private Vector3 ClampToLeash(Vector3 position)
    {
        Vector3 offset = position - AnchorPosition;
        offset.y = 0f;
        if (offset.magnitude > leashRadius)
        {
            offset = offset.normalized * leashRadius;
        }

        return AnchorPosition + offset;
    }

    public bool IsWithinLeash(Vector3 position)
    {
        Vector3 offset = position - AnchorPosition;
        offset.y = 0f;
        return offset.magnitude <= leashRadius;
    }

    public void SetPatrolEnabled(bool enabled)
    {
        if (patrolEnabled == enabled)
        {
            return;
        }

        patrolEnabled = enabled;
        if (!enabled)
        {
            hasPatrolTarget = false;
            pauseTimer = 0f;
            IsMoving = false;
            SetWalking(false);
        }
        else
        {
            hasChaseTarget = false;
        }
    }

    public void SetChaseTarget(Vector3 position)
    {
        chaseTarget = position;
        chaseTarget.y = transform.position.y;
        hasChaseTarget = true;
    }

    public void ClearChaseTarget()
    {
        hasChaseTarget = false;
    }

    public void StopMovement()
    {
        hasPatrolTarget = false;
        hasChaseTarget = false;
        IsMoving = false;
        SetWalking(false);
    }

    private void Move(Vector3 direction)
    {
        direction.y = 0f;
        if (direction.sqrMagnitude <= 0.001f)
        {
            IsMoving = false;
            SetWalking(false);
            return;
        }

        IsMoving = true;
        SetWalking(true);
        transform.position += direction * moveSpeed * Time.deltaTime;

        // 栓绳：任何情况下都不能完全离开基地
        Vector3 clamped = ClampToLeash(transform.position);
        clamped.y = transform.position.y;
        transform.position = clamped;

        transform.rotation = Quaternion.LookRotation(direction, Vector3.up);
    }

    private void SetWalking(bool walking)
    {
        if (animator != null)
        {
            animator.SetInteger("speed", walking ? 1 : 0);
        }
    }
}